Automatic control for looper pans



Nov. 27, w34.' F. E. FLYNN Er AL AUTOMATIC CONTROL FOR LOOPER PANS Filed Juiy 18, 1953 Nov. 27, 1934.. F, E. FLYNN ET A1.

- AUTOMATIC CONTROL FOR LOOPER FANS Inl.

Alll.

65E/PGE M HAR/VON (Ittornegs Patented Nov. 27, 1934 UNITED STATES AUTOMATIC CONTROL FOR LOOPER PANS Frank E. Flynn, Youngstown, and George N. Harmon, Warren, Ohio Application July 18, 1933, Serial No. 680,942

8 Claims.

This invention relates to continuous strip mills for rolling sheet metal and more particularly to looper pans employed in conjunction therewith and to apparatus for automatically operating the same in proper relation to the mills.

In a well known process of manufacturing sheet or strip metal a relatively short piece of metal of considerable thickness is fed thru a series of mills or stands of rolls arranged in tandem and l0 designed to gradually reduce the metal piece in thickness and to elongate the same. In certain types of strip mills the strip is carried by loopers or guides as it is passed from one stand to another so as to properly accommodate the elongated strip and to allow a loop to form of the slack in the strip between successive roll passes which compensates for variations in the different rolling speeds at the various elongating mills. The maintenance of loops or slack between the individual mills also prevents any possible elongation of the strip between the'mills which is ordinarily undesirable.

The guides or looper pans disposed between the successive roll stands insure the formation of the proper loop as well as serving to support the metal while in such looped positions. The proper operation of these looper pans prevents the formation of a'double, or other undesirable, loop or kink which may cause the metal to enter the succeeding mill double with subsequent breaking of the rolls or imperfections in the finished strip. However, in accordance with the teachings of the present invention, the looper pans should exert no elongating pressure or tension on the loop that they guide from one stand to another. `In addition the looper pans should be operated at the proper times in the elongation and passage oi' the strip to insure best results.

Heretofore, in strip mills the looper pans have 40 been manually operated or controlled necessitating a considerable number of operators. The time of the formation of the loop and its character as well as the upward pressure exerted on the metal strip was entirely within the discretion of the various operators. Thus variations in the quality and character of the strip produced naturally occurred due to the human element involved. Again unskilled or careless operators ofttimes caused trouble by improper operation.

It is an object of this invention to avoid and overcome the foregoing difficulties of prior practices by the provision of automatic means for fully controlling the looper mechanism in continuous strip mills. This invention provides a c'ontrol means for looper pans of such character that the loop is of a certain size and the next instant the loop may be either larger or smaller, and the device of the present invention causes or permits the pan to guide or follow the loop without at any time allowing the pan to exert suflicient force on the strip as to stretch the same.

The illustrated embodiment of our invention comprises a looper pan adapted to be operated through a suitable lifting jack. A motor operated lifting jack may be used in which the motor is connected to a source of current thru a relay operated by the motor driving the mill or roll stand immediately following the particular looper pan. Thus when the load on the mill motor is increased as the strip enters the stand. the relay is energized to close the electric circuit to the motor in the jack. Conversely when the strip leaves the aforesaid stand the reduction of the load on the mill motor opens the relay to cut olf the current supplied to the jack motor. The jack motor stops and suitable means such as counterweights cause the looper pan to return to its normal position.

In the drawings:-

Figure 1 is a side elevation of a section of `a continuous mill having disposed between adjacent stands thereof a looper pan constructed and controlled in accordance with our invention.

Fig. 2 is a top plan view of the apparatus disclosed in Fig. 1.

Fig. 3 is an enlarged sectional View illustrating the operating mechanism employed in raising and lowering the looper pan.

Fig. 4 is a diagrammatic View of the electric control employed in the embodiment of the present invention.

With reference to the drawings and in particular Figs. 1 and 2 the numerals 1 and 2 indicate generally a pair of roll stands arranged in tandem. It will be understood that in actual practice the number of mills or stands employed ordinarily exceeds two. However, the relationship of any number of stands is substantially the same as for two stands and accordingly two stands only have been completely illustrated and described. The

roll stands are of any standard form and have been illustrated as comprising a housing 3 in which are mounted upper and lower rolls 4 and 5. The housing 3 is secured to a base 6 which in turn is mounted upon a suitable foundation 7. The metal strip being rolled is indicated by the letter M and is adapted to pass through the rolls in the direction illustrated by the arrows, that is rst passing through roll stand 1 from which it is passed into the rolls of stand 2. Each of the roll stands 1 and 2 are provided with suitable entry guides 8 for directing the metal strip into the rolls and suitable delivering tables 9 for receiving the metal after it has passed through the rolls. These roll stands are ordinarily the conventional mills used in rolling strip and a further description is not thought to be necessary.

Intermediate the roll stands 1 and 2 is disposed a conveyor, generally indicated at 10, for transporting the metal between the two stands. This conveyor preferably comprises a xed pan table 11 and a looper pan 12, the latter being disposed adjacent the delivery end of the roll stand 1. The conveyor table 11 may be supported on a frame 13 having formed thereon an arcuate portion 14 received in a complementary bearing formed on a base 15. The frame 13 may be adjustably positioned so that the metal strip will be accurately introduced into the guides 8 and to this end a screw 16 engaging in an upwardly extending boss formed on the base 15 may support the end of the frame 13.

The looper pan 12 is adapted to be pivotally mounted between the roll stand 1 and the conveyor table 13 and for this purpose the pan 12 may be mounted on a plate 22 formed with a hinge boss 21 which receives a shaft 19. The shaft 19 may be journaled in U-shaped bearings 18 formed on suitable arms 17 which are preferably integral with the frame 13.

To control the movement of the looper pan 12 its support 22 may be formed with an integral lever bracket 23 which is preferably bifurcated to receive one end of a link 24 the opposite end of which is secured thru the agency of a crank 27 to a vertically disposed shaft 25 carried in the sleeve 26 mounted in the base 15. The opposite end of the shaft 25 through the medium of member 30 is operatively connected to rod 29 which in turn connects to suitable mechanism for automatically raising and lowering the looper pan.

With reference to Fig. 3 the mechanism for operating the looper pan may comprise a suitable mo-tor driven impeller illustrated as at 31 which has associated therewith a piston chamber 32 within which is mounted a piston 33. The motor driven impeller may be of standard form similar to those now on the market. Suiiice it to say that the impeller includes a centrifugal oil pump which creates an adjustable pressure behind the piston and that overloads on the piston will cause the same to resiliently yield even against the action of the impeller motor. Motive means of different construction but having the same operating characteristics may of course be used. Mounted on the outer end of the piston 33 is a boss 34 which receives one end of a link 35 which is connected to a bell crank 39 carried by a shaft 36. The shaft 36 may be mounted in bearing brackets 37 which are bolted to a foundation 38. The other end Vof the bell crank 39 is pivotally secured to a tie rod 40 which is connected to the rod 29 thru which the looper pan 12 is moved. In order to normally hold the looper 12 in a retarded position a counter Weight 43 may be utilized which can bey connected into the system by means of a bell lever 41, pivotally journaled at 42, which lever connects between the rods 29 and 40. A spring 49 may be connected between the looper pan 12 and the roll stand 1 as shown in Fig. 1. By employing different sized springs 49 and different weights 43 as well as changing the effective force of the impeller jack 31 metal strips M of various sizes and thicknesses can be handled.

The wiring diagram illustrated in Fig. 4 shows a manner in which the various parts of the combination can be connected together to give the the desired results. The numeral 50 indicates the electric motor of the roll stand 2 which motor is connected thru a control panel 52 to a source of current as at 54. A relay 56 is connected in series in one of the motor leads as indicated and is designed to control the relay switch 58 which closes the electric circuit to the motor 60 of the impeller jack 31. The relay is designed so that when there is no load on the roll stand 2 the relay switch 58 will remain open so that the impeller jack motor 60 will not be energized. However as soon as a strip of metal is fed into the roll stand 2 the load on the motor 50 will be increased causing the same to draw more current thus tripping the relay 56 and closing switch 58 to start the impeller jack motor 60 which raises the looper pan 12 as hereafter more fully described.

In the operation of the device with the strip M moving as indicated by the arrows in Fig. 1 it first passes between the rolls 4 and 5 of the roll stand 1 and the advancing end is discharged on the looper pan 12 and table 11 of the conveyor 10. The metal strip continues across the pan and table and is introduced into the guides 8 of the roll stand 2. Immediately upon the introduction of the metal between the rolls 4 and 5 of the roll stand 2 a load is placed on the motor 50 driving these rolls. This loading of the motor causes the relay 56 to close an electric circuit to the motor 60 controlling the impeller jack as above described. The energizing of this motor builds up pressure behind the piston 33 causing the same to move downwardly. Downward movement of the piston 33 causes the crank 39 to pivot about the shaft 36 to move the rods 40 and 29 outwardly and thus through the agency of connecting links 30, vertical shaft 25, links 27, 24 and arm 23, the looper pan 12 is tilted upwardly. pward movement of the pan 12 induces the formationy of a single properly formed loop in the metal strip M between the roll stands 1 and 2. The looper pan also serves to resiliently support the loop in the proper position and thereby prevents any stretching or improper looping or kinking of the metal strip. At such time as the downward pressure of the strip M on the looper pan 12 together with the weight 43 is sufficient to overcome the force of the impeller jack 31, the pan will yield resiliently in a downward direction. The discharge of the following end of the metal strip from the roll stand 1 causes the looper pan 12 to move upwardly. However continued movement of the strip M and the discharge' thereof from the rolls of the roll stand 2 relieves the load on the motor 50 driving these rolls so that the relay 56 associated therewith opens the circuit to the motor 60 driving the impeller jack 31 and thus completely relieves the pressure behind the piston 33. The weight 43 through the bell lever 41 immediately brings the looper pan 12 back to normal horizontal position adapted to again receive metal from between the rolls of the roll stand 1.

automatic control has been provided for the looper pans in a continuous strip mill line thereby.

substantially eliminating the human element causing error and bad work and at the same time reducing the number of operators required. The strip as it is run thru the various stands is mechanically formed into lops of the proper character at the proper time. The looper mechanism is such that it guides and supports the metal 4strip in all positions without stretching the same due to the resilient yielding and yet positive manner in Awhich the motor jack functions. Thus improper looping and kinking of the strip is prevented and at the same time a take-up or festooning device is provided between roll stands which allows a certain range of variation of the related speeds of the roll stands.

While in accordance with the patent statutes the invention has been specifically illustrated and described, it will be appreciated that the scope of the invention is not limited thereto but is defined in the appended claims.

What is claimed is:

1. The combination with a continuous strip mill having a plurality of roll stands having motors for driving the same, of means for guiding and supporting the strip between adjacent roll stands, said means comprising a vertically adjustable table, a looper pan associated with the table, a motor impeller jack for moving the looper pan to looping position, and a relay switch in the circuit of said motors for controlling-the ow of current to the motor impellerr jack, said on thel motor of the roll stand following'. the looper pan as occasioned by commencement ofl the strip rolling operation thereby.

2. The combination with a continuous strip mill having a plurality of roll stands and motors for driving the same, of means for guiding land supporting the strip between adjacent roll stands, said means comprising a looper pan, a motorimpeller jack for moving the looper pan to looping position, and a relay switch in the circuit of said motors for controlling the flow of current to the motor impeller jack, said relay switch in the circuit of said motors being closed by the increased load on the motor of the roll stand following the looper pan as occasioned by commencement of the strip rolling operation thereby.

3. The combination with a continuous -strip mill having a plurality of roll stands `having motors for driving the same, of means for guiding and supporting the Astrip between rollstands,

said means comprising a vertically adjustable table, a looper pan associated with the table, a vmotor impeller jack for moving theV looper pan to looping position, and a relay switch in the circuit of said motors for controlling the flow of current to the motor impeller jack.

relay switch being closed by the increased oaulv stands, a mechanism for. forming -a 'single' 4. The combination with-a continuous strip mill having a plurality of roll stands and motors for driving the sa e, of means for guiding and supporting the strip between adjacent stands, said means comprising a vertically adjustable table, a looper pan associated with the table, means for causing'the looper pan to resiliently l guide and support the strip with apredetermined force during the passage thereof between adjai cent roll stands and mechanism controlled by the load on the motor driving the roll stand following the looper pan forcontrolling the operation of the looper pan moving means.

5. The combination with a continuous strip mill having a plurality of roll stands and motors for driving the same, of means for guiding and supporting the strip between adjacent roll stands,

said means comprising a table, a looper pan associated with the table, means for causing the looper pan to guide and support the strip during the passage thereof between adjacent roll stands and mechanism controlled by the load on the motor driving the roll'stand following the looper pan for controlling the operation of the looper -pan moving means.

A6. The combination with a continuous strip mill having a plurality of roll stands and motors for driving'the same, of means for guiding and supporting the strip between adjacent roll stands, said means comprising a looper pan, means for causing the looper pan to resiliently guide and lol support the strip with a predetermined force during ,the passage thereof between adjacent roll `stands and mechanism controlled b`y the load on ythe'motor driving the roll stand following the looper pan for controlling the operation of the looper pan moving means.

7; In strip rolling mills, a pair of roll stands spaced intandem, motors for'driving said roll properly shaped kink free and unstretched loop between the roll stands, means energized by the increased load onsthe said motors due to 'rolling at theifollowing roll stand for controlling the operation of -theloop forming mechanism'and 120 means in said mechanism causing the mechanism to guide the `strip with a predetermined, pressure only and to yieldA if the strip exceeds thatpressure.

8. In strip' rolling mills, a pair of'roll stands 125 spaced in tandem, motors fordriving said roll. stands, a mechanism for forming a single properly shaped, kink free and unstretched loop between. the roll stands, and means energized by the increased load on the' saidmotors dueto rolling 130 at the following roll stand forcontrol li'ng the operation of the loop forming x'nechanism.l

'Gagnon N.v Hannon. 

